带有变量的python正则表达式替代组

Question

in python, need to substitute a group found in Regex string with a variable. but just substitute the group, not the entire regex result.

here is what I have so far:

content = "FILE_NAME(
           /* name */ 
           'test_name_to_replace.stp',
           /* time_stamp */ '2018-05-28T14:34:32+02:00',
           /* author */ (''),
           /* organization */ (''),"

replaceVariable = "New_Name.stp"
regex = r"(name.*\n*').*.stp"
subst = r"$1%s" % re.escape(replaceVariable)

New_Content = re.sub(regex, subst, content, 0, re.MULTILINE)

the result I from the search "regex" is:

name */ 
'test_name_to_replace.stp

where group 1 is

name */ 
'

and group 0 is

test_name_to_replace.stp

I need to keep group 1 and replace group 0 but the subs string isn't working the special character $1 before the variable, I get a result like this:

New_Content = "FILE_NAME(
           $1New_Name.stp',
           /* time_stamp */ '2018-05-28T14:34:32+02:00',
           /* author */ (''),
           /* organization */ (''),"

it deletes the group1

Answer 1

The documentation is always your friend, as this is very clearly documented in Regular Expression Syntax :

• \\number

  Matches the contents of the group of the same number.

But you don't need matching groups here, try using:

\\'(\\w+\\.stp)\\'

And then:

subst = "'{}'".format(replaceVariable)
re.sub(r"\'(\w+\.stp)\'", subst, content, 0, re.MULTILINE)

# Result
FILE_NAME(
           /* name */ 
           'New_Name.stp',
           /* time_stamp */ '2018-05-28T14:34:32+02:00',
           /* author */ (''),
           /* organization */ (''),